body {
  background-color: red;
}
div {
  background-color: red;
}
a {
  font-size: 14px;
}
.header {
  width: 200px;
  height: 200px;
  background-color: pink;
}
.header a {
  color: blue;
}
.nav::before {
  content: '';
}
.nav .logo {
  color: #fff;
}
